Fuel pumping device for internal combustion engines



July 18, 1933- E. A. RocKwELl. f 1,919,040

FUEL PUMPING DEVICE FOR INTERNAL COMBUSTION ENGINES Filed July 2. 1928Patented July 18, 1933 `PATENT OFFICE.;

EDWARD A.. BOCKXNELL, OF LONG ISLAND CITY, NEW YORK FUELy summe DnvlcnAFoa INTERNAL comBUsrIoN ENGINES Application med myu 2, icas. serial No.289,594.

The purpose of this invention is to. provide an improved construction ofa pumping device forl supplying fuel to the carbureter of an internalcombustion engine. It consists in theelements and features ofconstruction shown and described as indicated in the claims.

. cam Within adj acent an aperture thereof in Mechanically driven fuelpumps liave been designed for feedin fuel at a constant presoperatedthrough a constant stroke reciprocable lever carried by the'pump casingarranged to have a protruding armthereof. in thrust enga ement with anen ine driven tionconnection between the other arm of the lever and astem connected to the diaphragm.

- It is also old in apump construction, to use an interposed'spring inthe 'operating connection which, upon yielding, will limit the dischargeimpulse su ment. 3

It is a purpose of the present invention to provide a fuel pumpconstruction in which the diaphragm is 'ven a Vpositive suction strokeand a resiliently limited, discharge stroke throu h the use of an inteosed compression sprmg and to additionav y' employ a second compressionspring acting upon the jected to the pumping eleoperating lever in' sucha manner as to maintain the engine driven cam for its full stroke durmthe inactive phase of the cam and arrange to produce the dscharge strokeof the pumping diaphragm by acting through the inter-- posed compressionspring. .In the operation Q fa pump of this type, the suction willalion` required to draw the fuel frome engine casing wit a lost mover inthrust engagement with the;

the disways be produce/d positively while compression spring andresilientl limited by a second compression spring. t is alsodesirable'to so arrangesth'e discharge limiting spring that the frictionof the part guid' charge will be produced resiliently by a irst ed bythe pump casing will not detract from l the force of the limitingspring.

In the drawing: f Figure 1 is a diagrammatic view showing the locationof the pumping device with re.

spect to the engine 'carbureter and the fuel source on 'an automobile.

Figure 2 is an axial section of the pumping device, this sectionextending -to include the adjacent portion of the engine body upon whichthe pumping device is mounted.

In the construction` shown in the drawing,

the engine'body is indicated at A, the carbureter at B, the fuel .sourceat C, andl the pumping device in its entirety at D.

The pumping device comprises a casing structure consisting ,of twomembers," and 30. The member, 20l is adapted to be mount- Y ed upon thebody of the engine to be served, as seen at 20, having its cavitycommunieating with the cavity, a, of the engine body. Said member, 20,and the member, 30, are formed with mated iianges, 20? and 30h,encompassing cavities, 20 and 30, of said casing members respective-ly,adapted for clamping between them aflexible diaphragm, 40, whichconstitutesa mov-` ing wall of the chamber formed by /the cavity,hereinafter referred to as the pumping chamber.. 4Said pumping chamber1s connectedv for re ivin'g fuel supply from the fuel source by acondu1t,v50, whlch as shown comprises a sediment cup, x, f wellunderstood construction not a part of this invensaid flanges being tionand requiring no specific description,

in which conduit, an as shown in the outfiow passage, 505', of thesediment cup,-there is interposed a check valve, 50, opening for iniiowto the pumping chamber and seating against lreverse ow. The pumpingchamber is further connected by a pipe, ,60, leading to the carbureterin which there is interposed a valve, a, opening for outflow from thepumping chamber and seating against re- "45 chamber-enlarging verse iow.For operating. the diaphragm, 40, to flex it alternately in thedirections for enlarging and reducing the pumping chamber, saiddiaphragm 's provided with a two- 5 membered stem, of wllich one member,70, is positively connected to the diaphragm at the center thereof wheresaid stem serves also for clamping a central area of the diaphragmbetween disks, 41 and 42, the clamping being effected by a nut, 70,screwed onto the end of the stem member, 7 0, above the disk, 41.

The other stem member, 80, is tubular, that is, axially hollow, and isafforded slide bearing at 20d in the casing member, 20. This stem memberis connected at its lower end, as

seen at 80, with the inner end of a lever, 90, fulcrumed at 90a', in thecasing member, 20', and protruding from the casing member into theengine 'casing where its terminal,=,`90b, is positioned for .actuationby a cam, 10.0, on a rotating shaft, 101, of the engine. The stemmember, 70, is telescoped within thefstem member, 80, the latter havininwardly struck stop lugs, 80, past whic the lower end of the stemmember, 70, protrudes,and

Hbelow which said stem member, 70, is furnished with a stop nut, 7 0b,co-operatingwith the lugs, 80a, of the stem member, 80, for limiting theextension of the total rstem consisting of said two members. Within thestem member, 80, and aroundthe stem member, 7 0, there is positioned acoil spring, 7 5,y

` which is initially conditioned by compression for reacting at itsupper end against the under side of the diaphragm, 40,'and at its lowerend against the stop lugs, 80, for holdlng the two-membered stemextended to the limit determined by the co-operating stops, 80 and 70h.

'40 LIt wilLbe understood from the foregoing description that the lever,90, is actuated positively by "the cam, 100, in the direction foriiexing the diaphragm, 40, downwardly, that is,for giving said diaphragmitspumpingmovement; and` that for communicating t is pumpingchamber-enlarging movement, the two-meihbered stem is positivelyactuated in the direction for extending theI stem to the limitVdetermined by 5 0 the co-operating stops, 8l)EL and-7Gb, to which limithowever, the stem Ais already extendedI by the reaction of the spring,75, conditioned in the assembling of the parts by compression .for thuslreacting with predetermined force; 95 so that in the chamber-enlarging'lmovement ofthe diaphragm the two-membered stem operates as a rigid unit,its two members and the .spring which reacts between them for holds ingthe/stem extended being all moved togeth er positively .by thepositively actuated lever, l90. y

y For giving the lever, 90, ret'urn movement there is provided a spring,95, seatedin a cap, 20?, iiemovablysecured at the lower t end of thecasing member, 20, `and having at its upper end a-cap, 95, for seatin .adownwardly extending proj ection90", o the lever, 90, said spring beingconditioned by compression for normally reacting upwardly against thearm 'of the lever which engages the diaphragm stem, with predeterminedforce in l excess of .that needed to give the diaphragm itschamber-reducing movement for feeding the fuel to the carbureter. Foraccommodating the arcuate movement of the leverl at the end whichengages the diaphragm stem, the lever is slotted, as seen at 90d, forengaging the pivot pin, 80d, by which it is connected to the sleevemember, 80. 4

From the foregoing description it may be understood that the spring, 95,is conditioned by compression for reacting with greaterforce than thespring, 75, vwhichnormally holds the two-membered stern extendedto thelimit of the stops; but that the force with which the diaphragm performsits chamberreducing fuel feeding movement is determined by the reactionfor which the spring,

75, is conditioned by its initial compressionl of the force by which thefuel is fed l-to the carbureter.

I claim: y

1. In`a pumpin .device for supplying fuel to an internal com ustionengine, a pumping element yand operating connections theretov comprisinga lever arranged for positive actuation 1n one direction' only at oneend, and

connections from the other end tothe pumpi ing member,'said. connectionscomprisingla sprin by-which the connections are normally exten ed to apredetermined limit, said eX- tension being in the directionfromthe'point of engagement of the levercorresponding to the feedingmovement of the pumping member, and a spring reacting on the lever-inthe opposite direction from its positive actuation and in thedirection-for said feedingmovement of the pumpingI member, the' lastmenftioned spring being constructed for Jreactingl on the lever andthrough thelever on the first mentioned spring and through said lfirstmenjtioned spring on the pumping'member, the

second mentioned spring being conditioned for reacting more forciblythan the first/mentionedy spring. f f 2. Afuel pump for internalcombustion engines comprising' a pump casing adapted to b ejmounted onan engine casing-adjacent an aperture thereof, a y pumping diaphragmwithin said casingeadapted to cooperate with a pumping cham r on theupperside therehragm for limiting the discharge impulse iable dischargestroke of said spring, a second ported by the bottom' stem secured tosaid diating lever pivotally carried said lever having aneinof, adepending phragm, an opera y allowing a var through compression vcompression spring sup of said pump' casmg and acting upwardly lever armwith an overcome said inducing the discharge through said interthethrust enaid lever and the engine riven cam.

` EDWARD A. ROCKWELL.

by said pump casing, termediate ulcrum on said pump casing, said nged toextend into engage an engine tion connection between pending stem,positively to proroke of said dias positively moved an interposedspringbetween tion connection and said dialever having one arm arra saidengine casi driven cam, a lost mo vu on said last mentioned e ectiveforce suicient terposed spring for pro stroke of said diaphragm posedspring and maintaining agement between s the other lever arm and said desaid connection operating duce a positive suction hen said lever i bysaid cam, said lost mo lico-

